For a wire harness arranged in an engine room of a vehicle, a shield wire is used which has a drain wire provided together with an insulating covered electric wire. By installing the drain wire, noise can be more effectively prevented from being mixed in a signal supplied to a core wire of the insulating covered electric wire. Since the drain wire needs to be electrically connected to a braided wire for a shield, the drain wire itself is not coated with insulation.
However, when the shield wire is arranged in a watering area, for instance, when the engine room is to be cleaned, there is a fear that water droplets putting on the drain wire due to the watering area may move along the drain wire to be put on a circuit or circuit elements on a circuit board connected to the drain wire and give a damage such as a short-circuit accident thereto.
As compared therewith, a shield wire is proposed in Patent Literature 1 in which a water stop treatment is inexpensively applied to a drain wire. As shown in FIGS. 6 to 8, the shield wire 10 is arranged in a watering area of an engine room of a motor vehicle. A terminal of the shield wire 10 is connected to a connector 30. The connector 30 is fitted to a connector accommodating part of an ECU (not shown in the drawing) for an EFI (an electronically controlled fuel injection) arranged in the watering area. The water stop treatment is applied to the drain wire 11 drawn out from a peeled terminal of the shield wire 10.
As shown in FIG. 7, the shield wire 10 includes two insulating covered electric wires 12 (referred to as core wires 12, hereinafter) serving as signal lines and the drain wire 11. The drain wire 11 and the core wires 12 are sequentially coated with a shield layer 13 made of metal foil and a sheath 14. The drain wire 11 is allowed to come into contact with the shield layer 13 so as to be electrically conducted thereto. In the shield wire 10, the sheath 14 and the shield layer 13 are cut and peeled by the shortest dimension L of about 40 mm from an end to draw out the drain wire 11 and the core wires 12.
The drain wire 11 drawn out from the terminal of the shield wire 10 is formed with a twisted wire formed by twisting a plurality of strands. As shown in FIG. 8, the terminal side and the peeled end side of the drain wire 11 are coated with non-watertight thermal shrinkage tubes 15A, 15B to thermally shrink the terminal side and the peeled end side. Further, molten hot melt 16′ obtained by heating and melting a hot melt tube is infiltrated into the strands of the drain wire 11 between the non-watertight thermal shrinkage tubes 15A, 15B to fill the strands with the hot melt 16′ and solidify the strands.
A part from the non-watertight thermal shrinkage tube 15A of the terminal side of the drain wire 11 to the non-watertight thermal shrinkage tube 15B of the peeled end side is coated with a watertight thermal shrinkage tube 17 so as to cover an entire part of the position filled with the hot melt 16′ and thermally shrink that part. To an inner peripheral surface of the watertight thermal shrinkage tube 17, a thermally molten type water stopping agent 18 (refer it to as a “water stopping agent 18”, hereinafter) is previously applied. The water stopping agent 18 is molten during a thermal shrinkage to fill the position filled with the hot melt 16′ and outer peripheries of both sides in the axial direction thereof with the stopping agent.
In the drain wire 11 in the part filled with the hot melt 16′, the twisted wire is untwisted so that the hot melt 16′ is easily infiltrated between the strands. Further, to a boundary part between an end of the non-watertight thermal shrinkage tube 15A and a pressure contact part of a terminal 20, a rubber plug 21 is attached. The rubber plugs 21 are also attached to boundary parts between other core wires 12 and the terminals 20.